184 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



DESCRIPTION. 



Plants annual, branched at base, erect or spreading; culms as much as 1 meter tall 

 but usually less, smooth, or scaberulous below the pubescent nodes and below the 



panicle; sheaths smooth, scabrous, or sparingly 

 hispidulouB, often papillose, densely-ciliate, 

 pubescent or hispid on the collar; ligule a short, 

 densely ciliate membrane scarcely 1mm. long, 

 blades flat, mostly rather lax, erect or ascending, 

 straight, puberulent, and scabrous, as much as 

 25 cm. long and 1.5 cm. wide, usually less than 

 15 cm. long and 1 cm. wide; panicle loosely 

 flowered, narrow, tapering toward apex, mostly 

 less than 15 cm. long, the axis scabrous and, 

 except the lower part, also villous; branches 

 rather densely flowered, the lower somewhat 

 distant, sometimes as much as 2 or 2.5 cm. 

 long, spreading, usually 5 to 10 mm. long, 

 and, except the lower, approximate; ultimate 

 branchlets about 0.5 mm. long, bearing a single 

 spikelet and a single bristle below, the spikelet 

 sometimes rudimentary, thus bringing the 

 bristles in pairs; bristles 5 to 15 mm. long, 

 sometimes shorter, flexuous, antrorsely scabrous, 

 green or purplish; spikelets about 2 mm. long, 

 moderate] y turgid on the convex side ; first glume 

 U one-fourth to one-third the length of the spike- 



/■■M& let, 3-nerved; second glume a little shorter than 



the spikelet, 5-nerved; sterile lemma as long as 

 fig. 46.- ChaetocMoa grisebachii. From Met- the fertile lemma, 5-nerved, the palea small; 

 calfe 1262, New Mexico. fertile lemma acute, finely cross- wrinkled . 



DISTRIBUTION. 



Open ground, often a weed in fields, Texas to Arizona, south to Oaxaca. 

 Texas: Kerrville, Heller 1897. Limpia Canyon, Nealley 130. Austin, Hall 841. 



New Braunfels, Biltmore Herb. 14922. 

 New Mexico: Organ Mountains, Hitchcock 3786; Wooton & Standi ey in 1906. Mangas, 



Smith in 1897. Queen, Hitchcock 13520. Hillsboro, Metcalfe 1262. Without 



locality, Wright 2096. 

 Arizona: Santa Rita Mountains, Griffiths & Thornber 141, 266; Griffiths 3428, 6075; 



Wooton in 1914. Beaver Creek, MacDougal 606. Bowie, Jones 4288. Southern 



Arizona, Rothrock 676. Gardiners Spring, Pringle in 1882. Tucson, Hitchcock 



3514. Patagonia, Hitchcock 3662, 3679, 3681. Paradise, Blumer 1660, 1724. 



Sulphur Spring Valley, Griffiths 1901. Bisbee, Goodding 983. Clear Creek, 



Tourney 78 in 1891. San Bernardino Ranch, Mearns 2000. 

 Chihuahua: Chihuahua, Hitchcock 7774; Pringle 381. Sierra Madre, Nelson 6299. 

 Coahuila: San Lorenzo Canyon, Palmer 397 in 1904. Saltillo, Palmer 385 in 1898; 



Hitchcock 5626, 5641. Chojo Grande, Palmer 336 and 337 in 1904. 

 San Luis Potosi: San Luis Potosi, Parry & Palmer 957. 

 Durango: Torreon: Hitchcock 7546. Durango, Hitchcock 7573; Palmer 716 and 728 



in 1896. 

 Jalisco: Guadalajara, Hitchcock 7338, 7369. 

 Aguascalientes: Aguascalientes, Hitchcock 7461. 



